Wrong location error in log

Hi,

So I have suger cane farm, which keeps giving me these error messages in the server log:
11:38:18 [Server thread/WARN]: Wrong location! (93, -76) should be (93, -77), adw['item.item.reeds'/982809, l='world', x=1497.41, y=72.40, z=-1215.87]
11:38:18 [Server thread/WARN]: Wrong location! (93, -76) should be (93, -77), adw['item.item.reeds'/982811, l='world', x=1497.66, y=69.70, z=-1215.53]
11:38:18 [Server thread/WARN]: Wrong location! (93, -76) should be (93, -77), adw['item.item.reeds'/982812, l='world', x=1497.43, y=78.73, z=-1215.79]
11:38:18 [Server thread/WARN]: Wrong location! (93, -76) should be (93, -77), adw['item.item.reeds'/982821, l='world', x=1493.30, y=81.41, z=-1215.69]

Those locations are the top parts of the sugar cane. I can't replicate the process by triggering the farm, it just happens every know and then causing a little bit of lag. I'm still in the process of trying to figure out what is going on, if you need more info, just say so.